Shurflo water pump

Hi All, Having a problem with my Aqua King 3gpm water pump, story so far; changed original 1.85gpm Shurflo as would no longer run the shower, decided not to change diaphragm and buy new pump instead, however the new 3gpm is no better, have flushed out plumbing (plastic 15mm push-fit with flexible hose either side of pump)and all seems clear, checked output from pump and no way is it delivering 3gpm, the pipework from the tank is only about 1300mm long, biggest restriction on this would be the stop tap, all the rest is 15mm pipe/hose (as recommended by Shurflo)any ideas as to why it's not delivering enough flow, it's a virtually new pump. Thanks.

Hi All, Having a problem with my Aqua King 3gpm water pump, story so far; changed original 1.85gpm Shurflo as would no longer run the shower, decided not to change diaphragm and buy new pump instead, however the new 3gpm is no better, have flushed out plumbing (plastic 15mm push-fit with flexible hose either side of pump)and all seems clear, checked output from pump and no way is it delivering 3gpm, the pipework from the tank is only about 1300mm long, biggest restriction on this would be the stop tap, all the rest is 15mm pipe/hose (as recommended by Shurflo)any ideas as to why it's not delivering enough flow, it's a virtually new pump. Thanks.

Have you checked the stop tap is fully open?

I know this sounds stupid but some of us are!

When we first bought our boat the water pressure was dire and we also changed the pump, frustratingly, without effect.

We hadnít at that time managed to find the stop tap but when we did, a few extra turns to open it fully turned our trickling taps into torrents, we guess the previous owner who we had just bought the boat from had been a bit lazy when opening the stop tap after its recent winterising, or maybe they had struggled with it like that!

If it is fully open, it may not be operating properly, I understand some types have a poor mechanism that can unnecessarily restrict flow, perhaps due to furring up.

Another problem, I am told, can occur due to corrosion where different metals are used, e.g. mild steel fittings into stainless tank.

Thanks for replies, filter is clean, stop tap is fully open but this could well be the restriction, it's a washing machine tap and as it's intended for domestic water pressure I don't think they worry too much about maintaining the internal bore size, will have to try without it, I'll give that a go today.

Take the inlet pipe off the pumps nozzle, fit a length of hose on this with the other end in a bucket of water and see how it pumps by opening taps.

Thanks for replies, filter is clean, stop tap is fully open but this could well be the restriction, it's a washing machine tap and as it's intended for domestic water pressure I don't think they worry too much about maintaining the internal bore size, will have to try without it, I'll give that a go today.

Been at this all afternoon, checked flow from outlet side of pump (useless) connected hose to inlet side which was fed from a bucket, bingo good flow so it had to be the pipe from the tank to the pump, removed the stop tap (bit tricky with half a tank of water) tried again still poor flow, only thing left was tank connection, would take a month to empty using the Shurflo so had to remove water filler complete (three screws) so I could get the pipe in from a 240v water pump, pumped out most of the water then finished off slowly with the Shurflo, disconnected the pipework and spent a hour mopping up remnents still dripping from tank outlet, when it had finally stopped I checked the outlet and it was almost blocked, it's a steel tank and the builder has welded a steel pipe in for the outlet, guess over the boats 8 years the inside of the pipe has rusted and blocked it up, anyway got it cleaned out and reconnected the pipework, put some water in and tried the pump, gooood flow now even with the stop tap in place, brill, all I've got to do now is put everything back, tidy up and fill the tank, oh and check for leaks (very important)hope this will help others with an integral tank if suffering from poor water flow, sorry Shurflo I take it all back!!